Momentum is the rhythm of efforts along paths in the direction of interests. Rhythm is measured in beats of time.
Let's say we want to build our cooking repertoire in a specific style of cooking, like any ethnic cuisine. We decide how on the frequencies and durations of our efforts, that include research, videos, and experiments. We decide on an hour a week. We can change our momentum at any time, according to our experience and the rest of what's going on for us.
No deadlines need to be set. We simply adjust momentum for differently timed results. Again, without goals and deadlines, we are always feeling like we're succeeding.